1. Field of the Invention
The present invention relates to electric power control devices and electric power control methods for controlling electronic-device power consumption, and relates more particularly to electric power control devices and electric power control methods for controlling electronic-device operation according to the state of operational load on the electronic device.
2. Description of the Background Art
In recent years, electronic devices such as portable notebook computers, for example, are furnished with battery packs housing a battery that is usable while being repeatedly recharged. Thus, even in locations where no AC (alternating current) power supply is available, running the battery operates the system overall.
Against that backdrop, so-called low power consumption technology is under investigation to allow portable electronic devices, typified by these portable notebook computers and the like, to be used for extended periods even in locations where no AC power supply is available.
For example, in a computer device described in Japanese Laid-Open Patent Publication No. 2005-182522, the CPU (Central Processing Unit) is controlled to operate at either a high performance level or a low performance level based on the power supplied from the battery pack.
However, with computer devices of the conventional technology, source power supplied to the CPU is controlled based on battery information and on the power supplied to the CPU from the battery or elsewhere, and, in that situation, operation of the CPU is not controlled according to the use state (load state) of the CPU. A consequent problem has been, for example, that power consumption is minimized beyond necessity, such that the CPUs performance in the electronic device is not demonstrated.